Right now, Guns of Icarus is on sale. Earth, spitefire, and I have been playing for a week or two now and its a really great game. Go check it out here:
http://store.steampowered.com/app/209080/ ..and watch some gameplay on youtube. When I first started playing, the amount of players online ranged from 100-400, now that it's on sale there are currently 1400 playing. Even though it's been out for a while, the community is still growing and there are plenty of new people in the game. Y'all should check it out and consider it for a candidate for gaming on Tuesdays even though you can't really set up a dedicated server (that I know of).
Anyway, yeah! Check it out!